Dennis Quaid's twins normal despite overdose at birth

DENNIS Quaid's twins are "perfectly normal", despite being given a near-fatal overdose when they were babies.

The 61-year-old actor and wife Kimberly were left horrified when little Thomas and Zoe - who were born via a gestational carrier in November 2007 - were accidentally given a massive overdose of the blood thinner Heparin two weeks after they were born, but thankfully they have experienced no negative effects as they have grown older.

Dennis said: "They're perfectly normal as could be now. They're like head of their class."

The 'Big Easy' star admitted he and his wife went to a "dark place" when their kids were fighting for their lives, but always did their best to stay optimistic.

Speaking during a sneak peek of an appearance on Theo Von and Matthew Cole Weiss' podcast, 'Allegedly', which will be available in full tomorrow (08.12.15), he added: "You go to a dark place. But you gotta pull yourself away from that, you gotta remain optimistic. But everything turned out OK. We had a happy ending."

In December 2008, Dennis and Kimberly reached a $750,000 settlement with Los Angeles Cedars-Sinai hospital, while the facility was also fined $25,000 by the California Department of Public Health over the blunder.

The hospital also apologised to the families involved and said they were taking steps to improve staff training, and the 'Day After Tomorrow' star thinks terrifying experience brought some "good things".

He explained: "The hospital really stepped up and instituted a lot of patient safety that was very cutting edge and led the way with that.

"So a lot of good things came out of it, and I think a lot of lives got saved because of that ... The drug companies, or the hospitals, actually put my face on the bottle to remind people for a time!

"But you know, it's something that happens to you, you feel strongly about and you step up for it. It was really the kids that went through it and they were the ones that did it." .